Corneal endothelial cell density loss following glaucoma surgery alone or in combination with cataract surgery: A systematic review and meta-analysis

Efficacy analysis of microinvasive glaucoma surgery alone or in combination with phacoemulsification in patients with normal tension glaucoma: a systematic review and meta-analysis

OBJECTIVE

To assess the effectiveness of minimally invasive glaucoma surgery (MIGS) as monotherapy, or in combination with phacoemulsification, in the management of normal tension glaucoma (NTG).

METHODS

A systematic literature review and meta-analysis were conducted. The literature search was performed using four electronic databases, including Pubmed, Embase, Web of science, and Cochrane Central Register of Controlled Trials, to identify studies evaluating the efficacy of MIGS on patients with NTG, published from October 1, 2019 to October 1, 2024. The articles meeting our inclusion criteria were independently screened and assessed by three reviewers. Effect estimates associated with NTG were pooled and evaluated via meta-analysis. The articles retrieved from the databases were systematically analyzed using Citespace 6.2.R3.

RESULTS

A total of 11 English-language studies involving 413 eyes from 327 NTG patients were included. Follow-up ranged from 6 to 60 months. MIGS alone reduced IOP by 2.62 mmHg (95% CI: -3.70 to -1.54; Z = 4.77, P < 0.00001), while MIGS with cataract surgery reduced IOP by 2.09 mmHg (95% CI: -2.83 to -1.35; Z = 5.53, P < 0.00001). The number of IOP-lowering medications decreased by 1.47 with MIGS alone (95% CI: -2.16 to -0.77; Z = 4.07, P < 0.0001) and by 1.13 with combined surgery (95% CI: -1.75 to -0.52; Z = 3.63, P = 0.0003). No significant differences were observed between the two surgical approaches.

CONCLUSION

The meta-analysis demonstrated that either MIGS alone or combined with phacoemulsification effectively reduced the IOP and the requirement for IOP-lowering medications in NTG patients. MIGS alone or combined with phacoemulsification reduced the IOP most at 12 months, and the lowest IOP-lowering medications at 24 months in postoperative patients with NTG.

Trends in glaucoma surgery in a tertiary hospital in Spain: 2010-2022

ObjectiveThis study aims to conduct an analysis glaucoma surgeries performed over a 13-year period at a tertiary hospital affiliated with the Spanish National Health System, with the goal of assessing temporal trends.MethodsThis retrospective observational study scrutinized surgeries undertaken in the glaucoma unit of a tertiary center in Spain between 2010 and 2022. Data collected included surgical dates, procedure performed, whether it was standalone or combined, as well as patient demographics including age, sex, and type of underlying glaucoma. Surgeries on individuals under 18 years of age were excluded. An annual comparative analysis was performed to ascertain the evolving trends in glaucoma surgical interventions.ResultsA total of 12,944 surgeries were included in the analysis, comprising 9428 isolated cataract surgeries and 2975 glaucoma procedures. Trabeculectomy, glaucoma drainage devices (GDD), and cyclodestruction, collectively referred to as traditional surgery, demonstrated a decline from 93.2% to 23.6% over the study duration. Minimally invasive glaucoma surgery (MIGS) and minimally invasive bleb surgery (MIBS) demonstrated a significant increase from 3.8% in 2010 to 74.7% in 2022, relative to the total glaucoma surgeries. Furthermore, combined surgeries manifested a noteworthy increase from 39.0% in 2010 to 44.2% in 2022, with 86.4% of combined procedures in 2022 being MIGS or MIBS.ConclusionIn recent years, there has been a noticeable change in the trend of glaucoma surgeries, with MIGS and MIBS procedures experiencing a significant increase and becoming the most commonly performed glaucoma procedures. Consequently, traditional glaucoma surgeries have decreased in frequency.

Impact of preoperative intraocular pressure on corneal endothelial cell loss after phacoemulsification in acute primary angle-closure glaucoma with cataracts

Purpose

This study aimed to assess corneal endothelial cell loss (ECL) following phacoemulsification and intraocular lens implantation (Phaco+IOL) in eyes with acute primary angle-closure glaucoma (APACG) and cataracts under different preoperative intraocular pressure (IOP) levels.

Methods

This non-randomized controlled trial included 75 eyes from 75 patients with APACG and cataracts who underwent Phaco+IOL. All patients received pharmacotherapy and anterior chamber paracentesis before surgery and were grouped according to their preoperative IOP: the high-IOP group (IOP ≥ 25 mmHg) and the IOP-controlled group (IOP < 25 mmHg). IOP, visual outcome, endothelial cell density (ECD), hexagonality (HEX), coefficient of variation (CV), and central corneal thickness (CCT) were evaluated up to 3 months postoperatively. Baseline ECD, HEX, and CV parameters were measured in the contralateral eyes of all patients as a reference and compared with the postoperative results.

Results

The average IOP decreased from 43.2 ± 4.8 mmHg to 16.5 ± 5.8 mmHg (p < 0.001) in the high-IOP group and from 18.3 ± 4.3 mmHg to 14.3 ± 3.2 mmHg (p < 0.001) in the IOP-controlled group on the first postoperative day. The changes in IOP were more significant in the high-IOP group (p < 0.001). The ECD at 3 months was 1705.2 ± 503.8 cells/mm2 in the high-IOP group and 2091.8 ± 330.1 cells/mm2 in the IOP-controlled group (p < 0.001). The ECL rates at 3 months were 35.0% (high-IOP group) and 17.4% (IOP-controlled group) (p < 0.001). The postoperative changes in HEX and CV at 3 months were more significant in the high-IOP group (p < 0.001; p = 0.003). Both groups produced comparable improvements in visual acuity and IOP.

Conclusion

Uncontrolled high IOP (≥ 25 mmHg) before Phaco+IOL in patients with APACG and cataracts is associated with a higher rate of ECL. The rapid and substantial reduction of IOP during surgery may exacerbate corneal endothelial cell loss.

Clinical trial registration

ClinicalTrails.gov, identifier ChiCTR2100052096.

Investigation of Endothelial Cell Density after PreserFlo Implantation Compared to Contralateral Eyes without PreserFlo Implantation - A Retrospective Analysis

BACKGROUND

Loss of corneal endothelial cells after glaucoma surgery can lead to corneal decompensation and reduced vision. This loss may be accelerated by drainage implants like PreserFlo, which allow controlled subconjunctival filtration. In a retrospective analysis, we examined its impact on corneal endothelial cell density (ECD).

PATIENTS AND METHODS

Data from medical records for 94 eyes were retrospectively analyzed. This included 47 PreserFlo-operated eyes and 47 contralateral control eyes. Inclusion criteria were open-angle glaucoma, laser trabeculoplasty as the only prior glaucoma surgery, and a contralateral control eye without any previous glaucoma surgeries and without any relevant diseases. Only standalone procedures and pseudophakic eyes were considered. We included 48 eyes at 2 weeks (24 operated, 24 control eyes), 72 at 3 months (36 each), 34 at 1 year (17 each), and 36 at 3 years (18 each).

RESULTS

Preoperatively, the 47 eyes that were planned for surgery had a mean ECD of 2141 ± 527 cells/mm², and the 47 control eyes had an ECD of 2114 ± 561 cells/mm². Two weeks postoperatively, ECD decreased by 5.4% in the operated eyes and increased by 1.1% in the control eyes. After 3 months, endothelial cell loss (ECL) was 3.6% (operated) and 1.9% (controls). After 1 year, ECL was 11.7% (operated) and 5.6% (controls); after 3 years it was 7.6% (operated) and 2.9% (controls). No significant differences in ECL dynamics between the operated and control eyes were detected by the analysis of variance.

CONCLUSION

Although there was a trend to accelerated ECL in operated eyes compared to controls, this difference was not significant. Overall, the Preserflo procedure appears safe as regards to its influence on endothelial cell count.

Paul versus Baerveldt 350 glaucoma drainage implants: One-year comparative analysis

PURPOSE

This study aimed to evaluate and compare the effectiveness and safety of Paul glaucoma implant (PGI) and Baerveldt 350 glaucoma implant (BGI) over a 1-year follow-up period.

METHODS

This retrospective study was conducted in a private clinic. It compared 27 patients consecutively treated with the PGI to a historical cohort of 29 eyes that received the BGI prior to the introduction of the PGI between 2018 and 2023. Intervention: A new drainage device, the Paul implant, was placed in the anterior or posterior chamber of eyes with uncontrolled intraocular pressure (IOP).

MAIN OUTCOME MEASURES

The main outcome measures were success rate, final mean IOP, IOP reduction percentage, medication reduction, and complications. Statistical analyses, including adjustments for confounders, were used to compare the performance of PGI and BGI over at least a 12-month period.

RESULTS

Significant reductions in IOP were observed in both groups (P < 0.001). At 1 year, no significant differences were found in mean IOP (BGI: 12.0 mmHg, SD 2.9; PGI: 11.2 mmHg, SD 6.0) or medication usage (P > 0.05). The failure rates were 7% for BGI and 18% for PGI, with complete success rates of 56% for BGI and 32% for PGI. Hypertensive phases occurred in 32% of the BGI cases and in 19% of the PGI cases. No significant differences in the complication rates or postoperative visual acuity were observed between the groups.

CONCLUSION

PGI and BGI exhibited comparable efficacy and safety profiles after 1 year.

Cataract surgery combined with glaucoma surgery

PURPOSE OF REVIEW

This review evaluates the surgical management of glaucoma in patients undergoing cataract surgery. Combining both procedures present challenges in balancing intraocular pressure (IOP) control, minimizing postoperative complications, and achieving optimal refractive outcomes.

RECENT FINDINGS

Recent studies highlight the effectiveness of combined glaucoma and cataract surgeries, with traditional filtering surgeries and MIGS showing significant IOP reduction. The abundance of long-term studies shows that MIGS can offer an effective and safer alternative when carefully tailored to meet the specific needs of each patient.

SUMMARY

Combining glaucoma and cataract surgery is a promising approach for patients with coexisting conditions. While traditional surgeries offer robust IOP reduction, MIGS procedures offer better safety profiles with fewer complications and more predictable refractive results. Surgeons must carefully consider the timing and choice of procedures, with further research required to develop standardized treatment algorithms.

Comparison of treatment outcomes between slow coagulation transscleral cyclophotocoagulation and micropulse transscleral laser treatment

This study compared treatment outcomes of slow coagulation transscleral cyclophotocoagulation (SC-CPC, 65 eyes) and micropulse transscleral laser treatment (MPL, 134 eyes) in patients with medically uncontrolled glaucoma. Success was defined as achieving an intraocular pressure (IOP) of 6-21 mmHg with a ≥ 20% reduction from baseline, no reoperation for glaucoma, and no loss of light-perception vision. Visual acuity, number of glaucoma medication, corneal endothelial cell count, aqueous flare values, and complications were analyzed. At 12 months, mean IOP decreased from 32.2 ± 13.4 to 17.9 ± 8.3 mmHg in the SC-CPC group and from 26.4 ± 10.8 to 16.5 ± 6.8 mmHg in the MPL group. No significant changes were observed in visual acuity, medication count, or corneal endothelial cell count. Aqueous flare values increased immediately after the procedure and gradually decreased in both groups, with greater changes at 1 week significantly associated with greater IOP reduction (p < 0.05). Pupillary abnormalities were found in 5 eyes (4.5%) of the MPL group, with no severe complications. The 12-month success rates were 50.1% for SC-CPC and 38.2% for MPL (p = 0.131). Both SC-CPC and MPL effectively controlled IOP, with early postoperative aqueous flare values predicting treatment outcomes.

Changes in corneal endothelial cells after scleral-fixated intraocular lens surgery in children with congenital ectopia lentis: 2-year follow-up

PURPOSE

To investigate the changing patterns of corneal endothelial cells and the associated factors in children with congenital ectopia lentis (CEL) after scleral-fixated intraocular lens (SF IOL) surgery.

SETTING

Zhongshan Ophthalmic Center, Guangzhou, China.

DESIGN

Retrospective study.

METHODS

Patients were divided into the surgery group and the control group. Central endothelial cell density (ECD), coefficient of variation in cell size, the percentage of hexagonal cells (hexagonality), average cell size (AVG), and central corneal thickness were analyzed for both groups at baseline and each follow-up visit. Clinic characteristic, ocular parameters, IOL decentration, and IOL tilt of patients in the surgery group were collected. Multiple linear regression was performed to assess the potential associated factors for the postoperative changes in corneal endothelial cells in the surgery group.

RESULTS

After 2-year follow-up, the decline of ECD was 17.8% (95% CI, -21.8 to -13.9) in the surgery group and -3.1% (95% CI, -5.2 to -1.0) in the control group ( P < .001), while the increase of AVG was 24.3% (17.1-31.6) in the surgery group and 2.7% (1.0 to 4.5) in the control group ( P < .001). Multivariate analysis showed that axial length (AL) ≥24 mm and white-to-white (WTW) <12.2 mm were significantly associated with greater loss of ECD (β = -241.41, 95% CI, -457.91 to -24.91, P = .030 and β = 251.63, 95% CI, 42.10-461.17, P = .020, respectively) and AL ≥24 mm was significantly positively associated with the increase of AVG (β = 34.81, 95% CI, 0.90-68.71, P = .044).

CONCLUSIONS

The SF IOL had a significant impact on corneal endothelium in children with CEL. More attention should be paid to monitor postoperative corneal endothelium change during long-term follow-up in CEL children, especially for those with longer AL and smaller WTW.

Association Between Endothelial Cell Density and Corneal Thickness in Medium, Short, and Long Eyes of Han Chinese Cataract Patients

PURPOSE

To evaluate the association between the endothelial cell density (ECD) and central corneal thickness (CCT) in medium, short, and long eyes of preoperative Han Chinese cataract patients.

DESIGN

Retrospective cross-sectional study.

METHODS

We consecutively enrolled 410 eyes, namely, 50 short eyes (axial length [AL]<22.0 mm), 150 medium eyes (22.0≤AL<24.0 mm), 120 medium-long eyes (24.0≤AL<26.0 mm), and 90 long eyes (AL≥26.0 mm), of 410 adult patients scheduled for cataract surgery. The ECD and CCT were determined preoperatively with a noncontact specular microscope. The association between the CCT and ECD was identified by using a multivariable regression analysis. A thin cornea was defined as having a CCT less than 500 µm.

RESULTS

After adjusting for age, the presence of arterial hypertension, the presence of diabetes mellitus, intraocular pressure, and AL, a positive association between the CCT and ECD was identified in short eyes (linear regression coefficient [B]=3.40; standardized B [β]=0.52; P = .03), medium eyes (B = 2.33; β=0.28; P = .002), medium-long eyes (B = 1.84; β=0.25; P = .02), and long eyes (B = 2.69; β=0.41; P = .04). In the total group, the multivariable logistic analysis showed a significant link between the presence of a thin cornea and a lower ECD (odds ratio [OR]=0.80 per 100 cells/mm2 increase; P = .001).

CONCLUSIONS

For cataract patients of Han ethnicity, a significant association between a thin CCT and a lower ECD was shown across the AL spectrum and was most prominent in short eyes. Eyes with a thin cornea are more likely to have a lower ECD.

Corneal endothelial cell density and associated factors among adults at a regional referral hospital in Uganda: a cross-sectional study

BACKGROUND

To assess the prevalence of low corneal endothelial cell density and correlates of corneal endothelial cell density among adults attending Mbarara University and Referral Hospital Eye Centre in Uganda.

METHODS

In this hospital-based cross-sectional study, participants 18 years and older, were enrolled. We obtained informed consent, and basic demographic data. We also conducted visual acuity, a detailed slit lamp examination, intra-ocular pressure, corneal diameter, tear-film break-up time, keratometry, A-scan, and pachymetry on all participants. A confocal microscope Heidelberg HRT3 was used to examine the central cornea and to obtain the mean cell density (cells/mm2). To calculate the proportion of low endothelial cell density, descriptive statistics were used, whereas correlates of endothelial cell density were assessed, using linear regression analyses.

RESULTS

We evaluated a total of 798 eyes of 404 participants aged between 18 and 90 years (males = 187, females = 217). The average endothelial cell density was 2763.6 cells/mm2, and there was a decrease in endothelial cell density with increasing age, irrespective of gender. There was no significant difference in endothelial cell density between males and females. Increasing age (adjusted coefficient - 10.1, p < 0.001), history of smoking (adjusted coefficient - 439.6, p = 0.004), history of ocular surgery (adjusted coefficient - 168.0, p = 0.023), having dry eye (adjusted coefficient - 136.0, p = 0.051), and having arcus senilis (adjusted coefficient - 132.0, p = 0.08), were correlated with lower endothelial cell density. However, increasing corneal diameter (adjusted coefficient 134.0, p = 0.006), increasing central corneal thickness (adjusted coefficient 1.2, p = 0.058), and increasing axial length (adjusted coefficient 65.8, p = 0.026), were correlated with higher endothelial cell density. We found five eyes (0.63%) from different participants with a low endothelial cell density (< 1000cells/mm2).

CONCLUSION

Our study established baseline normal ranges of ECD in a predominantly black African population, and found that low ECD is rare in our population. The elderly, smokers, and those with past ocular surgery are the most vulnerable. The low prevalence could be due to a lack of reference values for the black African population.

Structural Priors Guided Network for the Corneal Endothelial Cell Segmentation

The segmentation of blurred cell boundaries in cornea endothelium microscope images is challenging, which affects the clinical parameter estimation accuracy. Existing deep learning methods only consider pixel-wise classification accuracy and lack of utilization of cell structure knowledge. Therefore, the segmentation of the blurred cell boundary is discontinuous. This paper proposes a structural prior guided network (SPG-Net) for corneal endothelium cell segmentation. We first employ a hybrid transformer convolution backbone to capture more global context. Then, we use Feature Enhancement (FE) module to improve the representation ability of features and Local Affinity-based Feature Fusion (LAFF) module to propagate structural information among hierarchical features. Finally, we introduce the joint loss based on cross entropy and structure similarity index measure (SSIM) to supervise the training process under pixel and structure levels. We compare the SPG-Net with various state-of-the-art methods on four corneal endothelial datasets. The experiment results suggest that the SPG-Net can alleviate the problem of discontinuous cell boundary segmentation and balance the pixel-wise accuracy and structure preservation. We also evaluate the agreement of parameter estimation between ground truth and the prediction of SPG-Net. The statistical analysis results show a good agreement and correlation.

Technological Advances in a Therapy of Primary Open-Angle Glaucoma: Insights into Current Nanotechnologies

Glaucoma is a leading cause of irreversible blindness and is characterized by increased intraocular pressure (IOP) and progressive optic nerve damage. The current therapeutic approaches for glaucoma management, such as eye drops and oral medications, face challenges including poor bioavailability, low patient compliance, and limited efficacy. In recent years, nanotechnology has emerged as a promising approach to overcome these limitations and revolutionize glaucoma treatment. In this narrative review, we present an overview of the novel nanotechnologies employed in the treatment of primary open-angle glaucoma. Various nanosystems, including liposomes, niosomes, nanoparticles, and other nanostructured carriers, have been developed to enhance the delivery and bioavailability of antiglaucoma drugs. They offer advantages such as a high drug loading capacity, sustained release, improved corneal permeability, and targeted drug delivery to the ocular tissues. The application of nanotechnologies in glaucoma treatment represents a transformative approach that addresses the limitations of conventional therapies. However, further research is needed to optimize the formulations, evaluate long-term safety, and implement these nanotechnologies into clinical practice. With continued advancements in nanotechnology, the future holds great potential for improving the management and outcomes of glaucoma, ultimately preserving vision and improving the lives of millions affected by this debilitating disease.

Clinical Factors Impacting Outcomes From Failed Trabeculectomy Leading to Glaucoma Drainage Device Implantation and Subsequent Penetrating Keratoplasty

PRCIS

We evaluated the factors that impacted time from glaucoma drainage implant (GDI) surgery to penetrating keratoplasty (PK) in eyes with previously clear corneas (ie, GDI-first sequence), and that specifically underwent a trabeculectomy before GDI surgery for intraocular pressure (IOP) control.

PURPOSE

To describe through an event-triggered data collection method the clinical course and the long-term outcomes of 2 procedures that are commonly performed sequentially in complex clinical situations: GDI surgery and PK. The study investigates the clinical factors associated with the progression to PK and determines the GDI success rate and graft survival.

METHODS

A single, tertiary-care center retrospective interventional cases series including patients with a sequential history of trabeculectomy, GDI surgery, and PK from 1999 to 2009. Outcome measures included IOP, visual acuity, graft failure, GDI failure, and time from GDI to PK.

RESULTS

Of the eyes, 56% had primary open angle glaucoma. The time from the last trabeculectomy to GDI was 66.5 ± 66.7 months. Of the eyes, 84% received a Baerveldt GDI. Time from GDI to PK was 36.4 ± 28.4 months. IOP at the time of PK was between 5 mm Hg and 21 mm Hg in 90% of eyes. At the last follow-up, 48% of grafts were clear. At 5 years post-PK, 33% of corneal grafts remained clear, whereas 81% of tubes remained functional.

CONCLUSIONS

Nearly half of the corneal grafts are clear at the last long-term follow-up. Graft failure occurs at a higher rate than tube failure suggesting that IOP control is only one and possibly not the most important factor in graft survival in eyes with prior glaucoma surgery.

Microinvasive glaucoma surgeries: critical summary of clinical trial data with and without phacoemulsification

PURPOSE OF REVIEW

To critically summarize and examine published data from randomized controlled clinical trials (RCTs) investigating the safety and efficacy of microinvasive glaucoma surgeries (MIGS) with and without cataract surgery versus cataract surgery alone.

RECENT FINDINGS

Three RCTs with standardized outcomes and rigorous methodology demonstrate superiority of the iStent (Glaukos), CyPass (Alcon), and Hydrus (Alcon) MIGS devices in combination with cataract surgery versus cataract surgery alone. The trials all involved medication washouts at baseline and also after 24 months of follow-up. In each of the trials, a greater proportion of participants randomized to the combined MIGS procedures achieved at least 20% unmedicated intraocular pressure (IOP) lowering compared with cataract surgery alone. With the exception of the CyPass device, which has been voluntarily withdrawn from the market, adverse events associated with MIGS were acceptable and consistent with routine intraocular surgeries. Follow-up studies demonstrate sustained efficacy, greater probabilities of visual field preservation, increased cost-effectiveness, and enhanced quality of life associated with MIGS procedures.

SUMMARY

Data related to MIGS platforms for treatment of open-angle glaucoma with or without co-existing cataract supports their continued adoption in clinical practice. Future studies comparing various techniques and devices in a standardized fashion are needed.

Six year outcomes of combined phacoemulsification surgery and endoscopic cyclophotocoagulation in refractory glaucoma

PURPOSE

This study is to describe the 6-year results of combined phacoemulsification surgery and endoscopic cyclophotocoagulation (Phaco-ECP) surgery in patients with uncontrolled glaucoma and no previous glaucoma surgery.

METHODS

This is a retrospective case series of 84 eyes. The primary outcome measure was intraocular pressure (IOP) reduction 6 years postoperatively. Secondary outcome measures were the cumulative probability of failure of the surgical procedure at 6 years. Failure was defined as IOP higher than 21 mm Hg or lower than 6 mm Hg or IOP not reduced by 20% from baseline at the 1, 2, 3, 4, 5, or 6-year time points or further laser or other surgery to reduce IOP at any timepoint.

RESULTS

There was a statistically significant decrease in mean IOP from 18.9 mmHg pre-operatively to 13.7, 12.8, 13.0, 12.7, 12.5, and 12.3 mmHg at the 1, 2, 3, 4, 5, and 6 years post-operatively respectively (p < 0.001). Fifty-seven (68%) reached criteria for failure by 6 years. In 36% of cases, this was due to inadequate IOP control, whereas 32% required further laser or surgery. When we excluded patients who only had selective laser trabeculoplasty rather than further surgery, the failure rate reduced to 51%. Eleven percent had a post-operative complication, 2.4% requiring further surgical intervention.

CONCLUSIONS

At 6 years postoperatively, combined phaco-ECP achieved a significant reduction in IOP in patients with uncontrolled glaucoma and no previous drainage surgery. Significant complications were uncommon, but 68% was classified as surgical failures by the six year point.